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Desmethylflunitrazepam molecular structure

Desmethylflunitrazepam Stats & Data

Depressant Research-chemical Benzodiazepine

Fonazepam Ro05-4435 Norflunitrazepam N-desmethylflunitrazepam

NPS DataHub

MW299.26

FormulaC15H10FN3O3

CAS2558-30-7

IUPAC5-(2-fluorophenyl)-7-nitro-1,3-dihydro-1,4-benzodiazepin-2-one

SMILESO=C1CN=C(c2ccccc2F)c2cc(N(=O)=O)ccc2N1

InChIKeyKNGIGRDYBQPXKQ-UHFFFAOYSA-N

Benzodiazepines; 2020/3. Benzodiazepine; 2021/3. Benzodiazepine; 2022/3. Benzodiazepine

Chemical Class Benzodiazepine

Psychoactive Class Depressant

Half-Life Not well established in humans for this specific metabolite; it is a long-acting active metabolite of flunitrazepam and can be present in urine for days after a single parent-drug dose; next‑day impairment is possible.

Pharmacology

DrugBank

Metabolism

Desmethylflunitrazepam is a known human metabolite of flunitrazepam.

Receptor Profile

Receptor Actions

Modulators

GABA-A receptor positive allosteric modulator (benzodiazepine site)

History & Culture

Desmethylflunitrazepam was originally identified as an active metabolite of flunitrazepam, the potent benzodiazepine marketed under trade names such as Rohypnol. The compound has since emerged on the grey market as a designer drug, sold online as a research chemical under names including fonazepam and the research designation Ro05-4435.

Effect Profile

Curated

Benzodiazepine 7.1

Strong anxiolysis, cognitive impairment, and euphoria with mild sedation

Anxiolysis×3

Sedation / Relaxation×2

Motor / Cognitive Impairment×1

Euphoria / Mood Lift×1

Based on reports from:

Erowid Experience Reports PsychonautWiki Desmethylflunitrazepam

Tolerance & Pharmacokinetics

drugs.wiki

Half-Life

Not well established in humans for this specific metabolite; it is a long-acting active metabolite of flunitrazepam and can be present in urine for days after a single parent-drug dose; next‑day impairment is possible.

Addiction Potential

High – rapid tolerance, pronounced psychological & physical dependence liability comparable to other high-potency benzodiazepines.

Tolerance Decay

Full tolerance 14d Half tolerance 7d Baseline ~21d

Benzodiazepine tolerance builds with repeated daily use and decays slowly over weeks after cessation; precise kinetics for desmethylflunitrazepam are not established. Cross‑tolerance across benzodiazepines is strong; partial cross‑tolerance exists to non‑benzodiazepine GABA-A hypnotics (Z‑drugs) and alcohol. Numbers above are heuristic markers for planning conservative spacing of doses and extended tapers, not pharmacokinetic half‑lives of the drug. Evidence base: clinical literature on benzodiazepine withdrawal/tolerance patterns and general BZD pharmacology.

Cross-Tolerances

Other benzodiazepines

100% ●●○

Z-drugs

50% ●○○

Alcohol

30% ●○○

Harm Reduction

drugs.wiki

• This drug is an active metabolite of flunitrazepam and a full positive allosteric modulator at GABA-A receptors; sedation, amnesia, and motor impairment scale steeply with dose. Mixing with other CNS depressants (alcohol, opioids, GHB/GBL, Z‑drugs, gabapentinoids, carisoprodol) greatly increases risk of respiratory depression, loss of consciousness, and aspiration. Naloxone reverses opioids but not benzodiazepines; if opioids are also involved, additional sedation may persist after naloxone.

• Very potent: sub‑milligram to low‑milligram active range. Use a calibrated 0.001 g scale and strongly consider volumetric dosing to avoid accidental overdosing or “redosing creep.” Clearly label solutions and store safely to prevent accidental ingestion by others.

• Profound anterograde amnesia is common at higher doses or in combinations; blackouts increase the risk of hazardous behaviors and unintentional redosing. Keep doses low, avoid alcohol, and consider a trusted sober sitter. Community reports specifically highlight blackout potential for related benzos; approach this compound with additional caution.

• Long‑acting: as an active flunitrazepam metabolite, norflunitrazepam and related metabolites can remain detectable in urine for days after a single dose; next‑day impairment is plausible. Avoid driving or operating machinery within at least 12–24 hours after dosing, longer if sedated.

• Polysubstance contamination: drug checking services repeatedly find benzodiazepines in illicit opioid (“benzo‑dope”) supplies, and mis‑sold benzo products occur. Use vetted services where available; assume unknown tablets/powders may not be what they claim.

• Dependence and withdrawal: daily use can lead to physiological dependence. Abrupt cessation may precipitate seizures, delirium, and severe rebound symptoms; any taper should be gradual and medically supervised. Antagonist flumazenil can precipitate seizures in dependent individuals and is not a routine HR strategy outside clinical settings.

• Insufflation is discouraged: absorption can be erratic and excipients may irritate nasal mucosa; oral/sublingual routes are safer for predictable dosing.

• Because products may come as micro‑tablets or blotters, confirm identity and concentration before dosing.